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What’s Force in quantum mechanics?

April 22, 2011

Mohan, mdashf

The electron scattered in an external field The 2nd Born approximation for the 3rd order term

This afternoon I was thinking of this. What’s Force in quantum mechanics.

I think more than 5 years ago while thinking deeply about this I asked myself “what’s force in qmech?” and I came up with the answer “Force is something that changes the possibilities or more aptly probabilities of outcomes and in quantum mechanics that would mean, changing the wavefunction ampitudes”.

Taking a clue from Feynman “all interaction is mass” therfore since interaction is force for every mass there is a force, that is, finding a new particle means the feynman amplitude diagrams have changed. SO all these things are internally related.

If we discover a hitherto unknown (new) particle it just means it had been changing the wave function amplitude but we did not know of it SO it may pertain to the form of a new force (or a old force might still explain it)

That is why in the recent sensation about a new bump found in CDF there was a discussion that we may have discovered a new fundamental force because this particle is not known in the list of things we know so far, called standard model.

This is also something I had said a while ago, 3 years to be precise, the LHC is capable of discovering many new physics, a 5th or 6th fudamental force is not out of question.

It just needs tremendous amount of study. My ideas can be found here in this article: Click on Me

Here is the code for drawing the above Feynman diagram [Technical Work of Manmohan Dash]

% Feynman diagram

% Requires PGF >= 2.0









:Title: Feynman amplitude diagrams for electrons scattered  in a field 3rd order 2ndborn approximation

The process is calculated in detail in Landau-Lifshitz’s Volume 4, 2nd edition.  (Quantum ED)



% Define styles for the different kind of edges in a Feynman diagram


photonvirt/.style={draw,blue,dashed, postaction={decorate},decoration={markings,mark=at position .35 with {\arrow[draw=red]{>}}}},

electron1/.style={draw,blue,thin,postaction={decorate},decoration={markings,mark=at position .25 with {\arrow[draw=blue]{->}}}},

electron2/.style={draw,blue,thin,postaction={decorate},decoration={markings,mark=at position .25 with {\arrow[draw=blue]{<-}}}},

electron3/.style={draw,blue, very thick,postaction={decorate},decoration={markings,mark=at position .35 with {\arrow[draw=red]{>}}}},

electron4/.style={draq,blue, very thick,postaction={decorate},decoration={markings,mark=at position .35 with {\arrow[draw=red]{<}}}},




        % Set the overall layout of the tree

        level/.style={level distance=1.5cm},

        level 2/.style={sibling distance=2.6cm},

        level 3/.style={sibling distance=3cm}


%[level 1/.style={level distance=10mm},

%level 2/.style={level distance=5mm}

\node [midway] (root) {q}

child[grow=south]{(q) to node (vp1) edge from parent [photonvirt] }{

child[grow=south]{(vp1)[\arrow{>}]edge [bend right] from parent [electron1]}

child[grow=south]{(vp1)[\arrow{>}]edge [bend left] from parent [electron2]}}{

child[grow=south]{node (vp2) {q} to node (vp3) edge from parent [photonvirt]}{

child[grow=-135]{(vp3) to node [below] (p’) {p’} edge from parent [electron3]}

child[grow=-45]{(vp3) to node [below] (p)  {p} edge from parent [electron4]}





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